A case of holocarboxylase synthetase deficiency with insufficient response to prenatal biotin therapy

Holocarboxylase synthetase (HCS) deficiency is an inborn error of biotin metabolism, leading to a multiple carboxylases deficiency. As the affected fetus sometimes presents with enlargement of the cerebral ventricles and intrauterine growth retardation (IUGR), prenatal administration of biotin has been attempted in some pregnancies. We present herein the case of a Japanese neonate with HCS deficiency who received maternal administration of biotin (10 mg/day) from 33 weeks’ gestation. After biotin administration, the fetal body weight increased and gestation was continued to full term. However, lactic acidemia and metabolic acidosis were observed after birth. To evaluate the effects of prenatal therapy, we collected serum samples and measured the acylcarnitine profiles using high-performance liquid chromatography electrospray ionization tandem mass spectrometry. At birth, levels of propionylcarnitine and 3-hydroxyisovalerylcarnitine had already increased. At 2 h after birth, these levels of acylcarnitines were further increased. At 3.5 h after the start of biotin, these chemical findings were slightly improved. In conclusion, we considered that prenatal biotin therapy at 10 mg/day may have been inadequate to avoid neonatal acidotic crisis in this case.     

A female case of ornithine transcarbamylase deficiency with marked computed tomographic abnormalities of the brain

The patient, 2 years and 9 months of age, was referred to our hospital with complaints of frequent vomiting, left hemiconvulsion and deep coma. The serum ammonia level was 251 micrograms/dl. Urine had a high orotate level (3,900 mumol/g creatinine). There was 7% residual of ornithine transcarbamylase (OTC) activity in the liver. Activities of other enzymes of the urea cycle were within normal limits. CT scanning on admission showed diffuse low density of both frontal lobes and of the right temporo-parietal lobe, narrowing of the right lateral ventricle and a shift of the mid-line to the left. The diffuse low density area was not enhanced after contrast medium injection. Follow-up CT scanning showed progressive bilateral ventricular dilatation and cerebral and cerebellar atrophy.     

Epileptic encephalopathy with microcephaly in a patient with asparagine synthetase deficiency: a video‐EEG report∗

Asparagine synthetase deficiency is a rare autosomal recessive neurometabolic disorder caused by mutations in the asparagine synthetase gene. It is characterized by congenital microcephaly, intellectual disability, progressive cerebral atrophy, and intractable seizures. A decrease in asparagine in CSF or plasma guides subsequent investigations in some cases, but normal values are described in other cases. Therefore, reaching a diagnosis is challenging and relies on exome sequencing. We report the case of a child with progressive microcephaly, irritability, startle reflexes, and jitteriness since birth. Focal clonic and myoclonic seizures, status epilepticus, and infantile spasms appeared in the first months of life. At first, the EEG showed multifocal epileptic activity which later turned into modified hypsarrhythmia and discontinuous activity. Brain MRI showed brain atrophy, a simplified gyral pattern, and poor myelination. Plasma asparagine levels were normal. Due to remote parental consanguinity, a study of contiguous regions of runs of homozygosity was performed, showing a 5‐Mb region (chr7:95629078–100679007) including the asparagine synthetase gene. The molecular analysis of this gene led to identification of a novel homozygous missense mutation, c.761G>T(p.Gly254Val), in our patient. The peculiar electroclinical phenotype may lead to diagnostic suspicion and molecular analysis which may benefit genetic counselling. [Published with video sequence].     

A case of carbamoyl phosphate synthetase 1 deficiency presenting symptoms at one month of age

Carbamoyl phosphate synthetase 1 deficiency (CPS1D) is an autosomal recessive disorder of the urea cycle which causes hyperammonemia. Two forms of CPS1D are recognized: a lethal neonatal type and a less severe, delayed onset type. Neonatal CPS1D cases often present their symptoms within the first days of life. Delayed onset type were adolescents or adults, and infantile cases were rare. We report a case of CPS1D in a boy who developed symptoms at one month of age. He showed excellent response to treatments including continuous hemodialysis, drugs and a low-protein diet. His development and weight gain were good at the last follow-up at 1 year and three months of age. Molecular assay of the CPS1 gene demonstrated that the patient was heterozygous for c.2407C>G (R803G: maternal) in exon 20 and c.3784C>T (R1262X: paternal) in exon 32. Our clinical experience suggests that CPS1D could be one of the causes of hyperammonemia in early infantile cases.     

Aromatic L-Amino acid decarboxylase deficiency: A new case from Turkey with a novel mutation

Aromatic L-amino acid decarboxylase (AADC), a vitamin B6-requiring enzyme that converts L-dopa to dopamine and 5-hydroxytryptophan to serotonin. Deficiency of this enzyme results in developmental delay, muscular hypotonia, dystonia, involuntary movements, autonomic dysfunction, and oculogyric crises. We now report a 2-year-old Turkish boy with AADC deficiency confirmed by greatly reduced AADC activity in the plasma and by genetic studies. Mutation analysis revealed a homozygous mutation c.208C > T (p. His70Tyr) in exon 3 of the AADC gene which has not been described to date.     

Prevalence of anemia and its relationship with neurological status in patients undergoing surgery for degenerative cervical myelopathy and radiculopathy: A retrospective study of 2 spine centers

Both degenerative cervical myelopathy (DCM) and anemia are common among older patients, however insufficient data exists evaluating their co-occurrence and the influence of anemia on baseline neurological status. To address this, we examined a retrospective multicenter series of patients treated for DCM or radiculopathy. Myelopathy was graded using the Nurick scale. Established criteria for diagnosing abnormalities were used to identify blood abnormalities, including macrocytic and microcytic anemia. Multivariable regression was used to determine the impact of hematological anomalies on Nurick grades. In our analysis, we included 725 patients (age of 57.1 ± 11.7), of whom 398 presented with myelopathy and 327 presented with radiculopathy alone. Twenty six percent of all patients were anemic at baseline and the mean preoperative Nurick grade across all patients was 2.09 ± 1.29; mean Nurick grade amongst those with DCM was 2.98 ± 1.12. Compared to those with myelopathy, patients with radiculopathy were significantly younger (53.8 ± 11.0 vs 59.8 ± 11.6, p < 0.001) and less likely to be anemic (16.8% vs 33.7%, p < 0.0001). Nurick grading was significantly higher in myelopathy patients with anemia (3.13 ± 1.19 vs 2.91 ± 1.07, p = 0.05) and macrocytic anemia (4.00 ± 1.41 vs 2.97 ± 1.11, p = 0.04). Multivariate regression demonstrated that anemia (p < 0.001), age (p < 0.0001), and posterior surgical approach (p < 0.0001) were related to worse preoperative Nurick grade. In sum, these data suggest that anemia and degenerative cervical spine pathologies commonly co-occur. Anemia, and macrocytic anemia specifically, is associated with poorer neurological status in myelopathic patients. These data suggest anemia may influence baseline neurological status and impact surgical recovery in patients treated for DCM or radiculopathy.     

A new case of total kininogen deficiency

Six families with total kininogen deficiency have been described in the literature. We report herein an additional case in a Pakistanese woman. The defect was discovered accidentally due to lack of normal clot formation in a preoperative routine blood sample. She had a borderline prolonged bleeding time, and reported occasional hematuria, but was otherwise without symptoms.

Absence of both kininogen species was proven by functional and immunological methods, and by lack of kinin formation both by plasma kallikrein and hog pancreas kallikrein. Prekallikrein was reduced, probably because the main part circulates complexed to high molecular kininogen.

Activation of intrinsic fibrinolysis was grossly hampered, and cold activation of coagulation absent with epsilonaminocaproic acid and greatly retarded by dextran sulfate, kaolin and ellagic acid.

Together with other evidence the findings indicate the following order of importance for contact activation in plasma - F.XII, high molecular weight kininogen, prekallikrein.     

A hereditary case of lipid storage myopathy with carnitine deficiency

Summary A case of lipid storage myopathy with systemic carnitine deficiency is reported. There was lipid storage also in the liver but not in leukocytes or the Schwann cells of peripheral nerves.Carnitine concentration was normal in the father but below normal in the mother's muscle where abnormal accumulations of lipid droplets and mitochondria were present between the myofibrils and beneath the sarcolemmal sheath. Histographic analysis demonstrated type I fiber predominance in the patient and in his parents. Hereditary transmission of the disease through a recessive autosomal mechanism might be admitted in this case.

---

Zusammenfassung Es wird ein Fall von Fettspeichermyopathie mit Karnitinmangel beschrieben. Die Fettspeicherung ist auch in der Leber, jedoch nicht in den Leukozyten und in den Schwannschen Zellen der peripheren Nerven nachweisbar. In den letztgenannten sowie im Muskelgewebe kann im Elektronenmikroskop eine Glycogen-Speicherung nachgewiesen werden, möglicherweise als unmittelbare Folge des Karnitinmangels auf dem Glycogen-Stoffwechsel.In der Muskulatur der Mutter des Exploranden kann ebenfalls eine zu niedrige Karnitinkonzentration nachgewiesen werden, wobei ein Überschuß an Fettröpfchen und Mitochondrien zwischen den Myofibrillen und subsarko lemmal sichtbar ist. Histochemisch läßt sich ein Überwiegen der Typ-I-Fasern sowohl beim Patienten wie bei den Eltern nachweisen. Die Autoren vermuten, daß im vorliegenden Fall die Krankheit rezessiv autosomal vererbt worden ist.

     

A female carrier of ornithine carbamoyltransferase deficiency masquerading as attention deficit-hyperactivity disorder

Many females who are heterozygous for ornithine carbamoyltransferase (OTC) deficiency are asymptomatic or intermittently symptomatic with great phenotypic variability. Therefore, the diagnosis of this condition is occasionally a challenge and is often delayed. A 12-year-old girl who was initially diagnosed as having attention deficit-hyperactivity disorder (ADHD) became comatose and developed right-sided hemiparesis during her psychiatric admission. Brain magnetic resonance imaging indicated diffuse but extensive swelling in the left hemisphere with multiple lesions suggestive of an old infarction. Repeated evaluations revealed hyperammonemia and orotic aciduria, and she was diagnosed as having an OTC deficiency. Genetic analysis revealed a heterozygous mutation of N47I in the X-linked OTC gene. Her mental status and hemiparesis improved after hyperammonemia treatment. Here, we report a rare case of a manifestating female carrier with severe symptoms of OTC deficiency masquerading as ADHD.     

A case of Ohtahara syndrome with mitochondrial respiratory chain complex I deficiency

Ohtahara syndrome (OS) is known as an intractable epileptic syndrome in neonatal and early infantile period, differentiated from early myoclonic encephalopathy (EME) in its etiology. We report a patient with OS associated with mitochondrial respiratory chain complex (MRC) I defect. With ketogenic diet and mitochondrial cocktail therapy, seizures were completely controlled and suppression-burst patterns disappeared 3 months after starting treatment. It is suggested that OS could be caused by specific metabolic disorder such as MRC defect and the intensive therapies including ketogenic diet, vitamin and coenzyme therapy and antioxidant treatment might be helpful for some patients.     

Randomized,placebo-controlled trial of ferric carboxymaltose in restless legs syndrome patients with iron deficiency anemia

ObjectiveIntravenous ferric carboxymaltose (FCM) has been shown to be efficacious in treating restless legs syndrome (RLS) symptoms in non-anemic patients. The aim of this study was to evaluate the effectiveness of FCM in treating RLS symptoms in patients who also had an iron deficiency anemia (IDA).MethodsThis is a randomized, double-blinded, placebo-controlled study. Subjects with RLS and IDA were enrolled. Subjects received an infusion of either 1500 mg FCM or placebo in Phase I. The primary outcomes were a change-from-baseline at week six on the International Restless Legs Syndrome Study Group scale (IRLS). Phase II of the study involved long-term (52 weeks) follow-up, for those who responded to treatment in the prior phase, with the potential for further treatment if symptoms returned.ResultsWe enrolled 29 RLS patients with IDA (15 FCM and 14 placebo). At week six post-infusion, FCM compared to placebo group showed significant improvement from baseline in IRLS score (−13.47 ± 7.38 vs. 1.36 ± 3.59). Among secondary outcome variables, quality of sleep showed significant improvement from baseline in the FCM group. 61% of subjects remained off RLS medications at the Phase II, week-52 endpoint. There were no serious adverse events observed in the study.ConclusionThe study showed significant efficacy and safety of FCM 1500 mg treatment both in the short term (6 weeks) and long term (52 weeks) in RLS patients with IDA.     

A case of QARS1 associated epileptic encephalopathy and review of epilepsy in aminoacyl-tRNA synthetase disorders

IntroductionMutations in QARS1, which encodes human glutaminyl-tRNA synthetase, have been associated with epilepsy, developmental regression, progressive microcephaly and cerebral atrophy. Epilepsy caused by variants in QARS1 is usually drug-resistant and intractable. Childhood onset epilepsy is also reported in various aminoacyl-tRNA synthetase disorders. We describe a case with a milder neurological phenotype than previously reported with QARS1 variants and review the seizure associations with aminoacyl-tRNA synthetase disorders.Case reportThe patient is a 4-year-old girl presenting at 6 weeks of age with orofacial dyskinesia and hand stereotypies. She developed focal seizures at 7 months of age. Serial electroencephalograms showed shifting focality. Her seizures were controlled after introduction of carbamazepine. Progress MRI showed very mild cortical volume loss without myelination abnormalities or cerebellar atrophy. She was found to have novel compound heterozygous variants in QARS1 (NM_005051.2): c.[1132C > T];[1574G > A], p.[(Arg378Cys)];[(Arg525Gln)] originally classified as “variants of uncertain significance” and later upgraded to “likely pathogenic” based on functional testing and updated variant database review. Functional testing showed reduced solubility of the corresponding QARS1 mutants in vitro, but only mild two-fold loss in catalytic efficiency with the c.1132C > T variant and no noted change in tRNA^Gln aminoacylation with the c.1574G > A variant.ConclusionWe describe two QARS1 variants associated with overall conserved tRNA aminoacylation activity but characterized by significantly reduced QARS protein solubility, resulting in a milder clinical phenotype. 86% of previous patients reported with QARS1 had epilepsy and 79% were pharmaco-resistant. We also summarise literature regarding epilepsy in aminoacyl-tRNA synthetase disorders, which is also often early onset, severe and drug-refractory.     

Parieto-occipital encephalomalacia in neonatal hyperammonemia with ornithine transcarbamylase deficiency: A case report

Urea cycle disorders are congenital metabolic disorders that often cause episodic hyperammonemia. Neuroimaging in episodic hyperammonemia demonstrates several patterns of brain injuries, including focal lesions in the lentiform nucleus, insula, cingulate gyrus, and perirolandic fissure, as well as diffuse cerebral edema. In cases with neonatal onset of hyperammonemia, similar lesions have also been reported. We herein report a boy with severe neonatal hyperammonemia caused by ornithine transcarbamylase deficiency. He presented with parieto-occipital encephalomalacia, which resembles severe neonatal hypoglycemia on magnetic resonance imaging. This radiological finding may indicate parieto-occipital vulnerability not only to hypoglycemia but also to hyperammonemia.     

An autopsy case of acute porphyria with a decrease of both uroporphyrinogen I synthetase and ferrochelatase activities

Summary An autopsy case of a 37-year-old woman with acute porphyria is reported. The patient began to complain of severe menstrual pains, and later developed serious peripheral neuropathy and various autonomic nervous symptoms.The autopsy revealed a marked loss and degeneration of axons and myelin sheaths in the peripheral nervous system (PNS), and prominent central chromatolysis of the spinal anterior horn cells. The predominant process of the peripheral neuropathy appeared to be axonal degeneration.Biochemical analysis showed a marked increase of delta-aminolevulinic acid (ALA), porphobilinogen, uroporphyrin, and coproporphyrin in the urine, and an increase of coproporphyrin and protoporphyrin in the stools and blood. In the analysis of the enzymatic activities of the liver and bone narrow, the activity of ALA synthetase (ALA-S) was markedly increased, and the activities of both uroporphyrinogen I synthetase (URO-S) and ferrochelatase were decreased. It was characteristic in this case that the enzymatic abnormalities found in both acute intermittent porphyria (AIP) and variegate porphyria (VP) coexisted.Biochemical analysis of the sciatic nerve showed an increase of ALA-S activity and a decrease of both URO-S and ALA dehydrase activities. This was the first report that indicated the presence of abnormal activities of the heme biosynthetic enzymes in the peripheral nerves of porphyric patients. The possibility was discussed that these enzymatic abnormalities of the heme biosynthesis in the peripheral nerve itself might be strongly related to the pathogenesis of the porphyric neuropathy.     

A new mutant strain of syrian hamster with myelin deficiency

Summary A new disorder of central myelination was found in black mutant hamsters showing trembling. The condition was inherited in an autosomal recessive mode. Histologically, a marked myelin deficiency was distributed throughout the central nervous system (CNS), and it was closely related to clinical manifestations observed in the mutants Ultrastructurally, abnormally thin myelin sheaths were observed in all axons with different diameters, and most axons below 1 m in diameter were unmyelinated in the white matter of the spinal cord. There was no overt evidence of demyelination, but some myelin sheaths showed an aberrant configuration. The numbers of glial cells were not reduced, and there were no striking morphological abnormalities in them. It was suggested that there may be a dysfunction of oligodendrocytes resulting in retarded or defective myelination. This trembling hamsters may be a suitable animal model for the study of normal and abnormal myelinogenesis.     

Rehabilitation of gesture imitation: A case study with fMRI

Acquired disorders of gesture imitation are amenable to treatment, but with poor generalisation toward gestures not included in the training program. We investigated the neural basis of this item-specific recovery in a patient with a slowly progressive posterior cortical atrophy, by means of an fMRI study comparing imitation of rehabilitated and not-rehabilitated gestures. Results suggested that in our patient gesture imitation recruited the mirror system and additional areas relevant to gesture analysis and preparation. Imitation of rehabilitated gestures activated the mirror neuron system, and also left dorsolateral prefrontal cortex and putamen, and the right anterior temporal cortex. This suggests that item-specific recovery was based on interaction of circuitry of imitation with neural systems involved in emotional and motivational processing.     

A case of CPT deficiency, homoplasmic mtDNA mutation and ragged red fibers at muscle biopsy

A 45-year-old male patient had an episode of acute renal failure with myoglobinuria, myalgias, weakness, and markedly increased serum CK levels. Similar episodes had occurred in the past. Carnitine palmitoyl-transferase II (CPT II) deficiency was documented both biochemically and genetically. Interestingly, muscle biopsy also showed some ragged red fibers (RRF) and complete mitochondrial DNA (mtDNA) sequence disclosed a homoplasmic T3394C point mutation. This mutation is described in Leber's hereditary optic neuropathy (LHON) or in patients with diabetes mellitus.     

A case of late-onset carbamoyl phosphate synthetase I deficiency, presenting periodic psychotic episodes coinciding with menstrual periods]

Carbamoyl phosphate synthetase I deficiency (CPSID) is a rare metabolic disorder affecting the first enzymatic step of urea cycle. We report clinical manifestations of a female case of late-onset CPSID in Japan. An 18-year-old girl was admitted to emergency room due to acute comatose state. Her parents had no apparent consanguineous history. She had suffered from intermittent psychotic episodes (excitation, aggressive behavior and insomnia) with nausea and vomiting from the age of 13, mostly coinciding with menstrual period. She had minor learning disability without major neurological deficits and convulsions. Her mental status was estimated as normal in her intermenstrual period. She had been diagnosed as having hysteria and premenstrual syndrome. Her neurological findings on admission showed deep coma and hypotonic tetraparesis. Plasma ammonia level was markedly elevated (684 micrograms/dl) without significant liver dysfunction. Blood urea nitrogen decreased to 6 mg/dl. Continuous venovenous filtration with subsequential administration of sodium benzoate and l-arginine was started to eliminate blood ammonia. Although the plasma ammonia level decreased to 300 mu/dl in next 10 hours, severe cerebral edema was observed in head computed tomography subsequently, followed by marked cerebral atrophy. Finally, her consciousness status became almost alert a month after the onset, but her mental status was severely retarded. CPSI activity of her biopsied liver markedly decreased and she was diagnosed as having CPS ID. CPSI cDNA analysis of her biopsied liver demonstrated a V1149G mutation. Genomic DNA analysis showed that she was heterozygous in V1149G mutation. The mutation allele was derived from her father. The causative factor for absence or very low level of maternal CPSI mRNA will require further analysis.